1. Field of the Invention
The present invention relates to a piezoelectric vibrator, an oscillator, an electronic apparatus and a radio controlled timepiece.
2. Background Art
For example, in a cellular phone or a portable information terminal apparatus, a piezoelectric vibrator utilizing crystals or the like is often used as a device which is used in a time source, a timing source of a control signal or the like, a reference signal source or the like. As this type of the piezoelectric vibrator, a piezoelectric vibrator is known in which a piezoelectric vibrating piece is hermetically sealed within a package in which a cavity is formed.
In the package described above, the cavity is formed by utilizing a concave section, which is formed by overlapping one substrate in which the concave section is formed with another substrate and by bonding both the substrates.
The piezoelectric vibrating piece includes a pair of vibrating arm sections that are disposed in parallel side by side in a width direction and a base that supports the side of a base end of the pair of vibrating arm sections in a cantilever manner, and is configured to vibrate (oscillate) with a predetermined frequency so that the pair of vibrating arm sections separate from or approach each other in a width direction starting from the side of the base end section thereof.
In the piezoelectric vibrating piece, a mount electrode formed in a mount section of the base section is bonded to a leading-out electrode formed on the substrate of the package by a conductive adhesive, a metal bump or the like.
However, when operating the piezoelectric vibrating piece, it is known that vibration leakage (leakage of vibration energy) occurs from the mount section of the base section to the side of the package. If the vibration leakage occurs, since a resonance frequency of the piezoelectric vibrating piece is no longer stable, it is necessary to suppress the vibration leakage as much as possible.
Thus, a piezoelectric vibrating piece including a pair of vibrating arm sections extending along each other, a base section to which each base end of the pair of vibrating arm sections is connected, and a support arm section that is connected to the base section between the pair of vibrating arm sections and extends from the base section along the vibrating arm sections is disclosed in JP-A-2003-163568, JP-A-2006-345517 and JP-A-2006-345519. Then, a configuration is disclosed which suppresses the vibration leakage and stabilizes the vibration of the vibrating arm sections by securing a long distance from the mount section in the support arm section to the vibrating arm sections.